December 2005

Taxotere ®, a chemotherapy drug made from the needles of the European yew tree, improves the survival time and quality of life for men with advanced stage prostate cancer that is resistant to hormone therapy. The drug, which has been used since 1995 in the treatment of breast and lung cancer, kills cancer cells by disrupting the formation of their internal structures, thereby stopping cells from dividing and multiplying. That Taxotere ® shows promise in the treatment of prostate cancer is good news. In the past, few prostate cancers responded to even very strong chemotherapy drugs, and chemotherapy offered a poor ratio of benefits to risks for men with metastatic disease. (For an excellent article on the use of chemotherapy in treating metastatic prostate cancer, see the ProCure Alliance website.)

Research indicates that chemotherapy will become increasingly more common in the treatment of prostate cancer. A recent global study (TAX 327) provides evidence that men given Taxotere ® every three weeks (in combination with prednisone) survived approximately 2.4 months longer than those in the control group. (The control group received Mitoxantrone, another chemotherapy drug, which has been shown to reduce the symptoms and pain of patients but which does not significantly extend their lives.) Researchers conducting the trial reported that those using Taxotere ® experienced less pain (by more than 50 per cent) and a significant lowering of their prostate specific antigen (PSA) levels. While the drug's ability to extend life for two to three months may not seem a huge improvement, it is encouraging. "Taxotere is the first chemotherapy drug to demonstrate a statistically significant survival benefit for men with androgen-independent prostate cancer," says Dr. Eric Winquist, one of the Canadian TAX 327 researchers.

But what is "androgen-independent" prostate cancer? Basically, it is prostate cancer that is not responding to hormone therapy, the most common treatment for those with advanced stage prostate cancer. Hormone therapy consists of reducing the supply of androgens (male sex hormones) to the tumor by either removing the testicles, suppressing hormone production with chemicals, or blocking the effects of androgens on cancer cells using anti-androgen drugs. Unfortunately, hormone therapy often stops working after a time. The cancer cells learn to divide without male hormones, and the cancer becomes hormone refractory or androgen-independent; it is resistant to hormone therapy.

Click here for information on Dr. Ian Tannock's March 8, 2005 address to the Brampton Chapter of CPCN. His speech "Hormone Therapy and Chemotherapy in the Treatment of Prostate Cancer," discusses the use of these therapies in the treatment of a hypothetical patient aged 68 who seeks help because of bone pain and is diagnosed with metastatic prostate cancer.

Because approximately 80 per cent of prostate cancer patients with advanced disease respond to hormone therapy initially but relapse within an average of two years, having a chemotherapy drug such as Taxotere ® available in the treatment arsenal is helpful. Side effects of treatment may include low blood counts, fever, fatigue, hair loss, and nausea. However, TAX 327 researchers report an overall improvement in the quality of life of those treated with Taxotere ® . Further trials studying the effectiveness of using this drug to treat aggressive prostate cancer at an earlier stage are planned.

Currently, Health Canada, the FDA, and the European Commission have approved the use of Taxotere ® for the treatment of androgen-independent metastatic prostate cancer. Also, all provinces in Canada include Taxotere ® in their treatment guidelines for men with advanced stage, hormone resistant prostate cancer. As Dr. Saad, Director of Urologic Oncology for the Hôpital Notre-Dame, comments, "Given that one in every seven men is diagnosed with prostate cancer, and that about one in four of these men eventually progress to a refractory state, the approval of Taxotere gives Canadian prostate cancer patients some very positive news."

Taxotere ® is the product of Sanofi-aventis, which has its Canadian headquarters in Laval, Quebec.